Wheat acreage across the Midsouth region has been historically low for several years, but there appears to be some renewed interest as we arrive at planting time this season. Thankfully, drier weather is allowing harvest progress, tillage, and field preparation, which may encourage more wheat planting this fall.
Regardless, wheat is a relatively consistent crop that does offer some benefits and diversity from being a “winter” crop. Wheat grown utilizing good management can produce 70 to over 100 bushels per acre in Mississippi. The primary environmental limitations to wheat productivity in Mississippi are high spring rainfall (particularly during April and May), late spring freezes, and abnormally warm temperatures during the winter.
This article will address key planting and management practices to optimize wheat productivity and profitability.
Field selection is important: The wheat growing season occurs during the wettest months of the year, so good soil drainage is absolutely critical to high productivity. Avoid selecting fields with little grade, potential water ponding, or other drainage issues. Also, heavy clay soils usually retain water considerably longer than coarser soils, further compounding problems. Therefore soil and field properties which encourage drainage are vital because they promote aeration necessary for vigorous plant growth.
Yield potential is very dependent on fertility: Wheat productivity is very responsive to fertility. Wheat is a shallow-rooted crop grown during the wet-season, so it is quite vulnerable if any nutrient shortcomings exist. To reiterate, yield potential is correlated to whatever nutrient is most limiting – so although nitrogen management is crucial, we must address all fertility needs. Most fertility issues, with the exception of nitrogen and sulfur, should generally be addressed before planting. Furthermore, if you plan to double-crop behind the wheat, it is best to address both crops’ needs prior to planting wheat.
You must start clean at planting: It is absolutely essential to kill weeds before planting wheat. Maintaining a weed-free environment during planting and stand establishment is essential because weeds are very competitive with young wheat plants, particularly if they emerge before or at the same time as the wheat crop. This can be done by either applying a burndown herbicide or using tillage. Tillage may be the most practical option to control volunteer Roundup Ready corn prior to planting wheat.
Variety selection: Selecting a well-adapted wheat variety may be more important than any other crop grown in Mississippi, because there is considerable genetic diversity amongst varieties which can substantially affect performance in different regions of the state. Those varieties best adapted for south Mississippi are generally much earlier in maturity, compared to those best adapted to north Mississippi and the Delta. Therefore, don’t make the mistake of picking an early maturing variety exclusively to allow for earlier double-cropping in north Mississippi, because it is much more vulnerable to a spring freeze than well-adapted varieties for that region. Complete variety suggestions are available here: 2021 Wheat Variety Suggestions
Early planting is normally counter-productive: Contrary to most summer crops, early planting is usually rather detrimental to high wheat grain yields in our region. Early planting often promotes excessive growth, particularly when temperatures are warm during the fall, which greatly increases the likelihood of spring freeze injury and numerous pest and disease problems. Our mild southern winters amplify this issue, because the onset and degree of wheat dormancy may vary greatly from year to year. A good rule of thumb is that wheat planting should coincide with the first frost date in the fall. This date can vary considerably depending upon seasonal temperatures, but generally corresponds to late October to early December, depending on latitude.
Use an appropriate rate for your seeding method: Wheat productivity is not generally very responsive to seeding rate, as long as you achieve a vigorous, healthy, stand. This is because wheat readily tillers, or produces multiple stems to optimize its productivity. Accordingly, controlling fall weed competition and providing adequate fertility are also critical to tillering and early plant development. Our normal planting recommendation is to strive to establish 1.0 to 1.3 million wheat plants/acre or 23 to 30 plants/square foot regardless of seeding method. Wheat seed size can range from under 10,000 to over 16,000 per pound, so we should use seed number to determine appropriate seeding rates. The following table lists appropriate seeding rates for planting wheat with a drill, where 85% or higher stand establishment is typical.
Broadcast seeding rates: Higher seeding rates are required for broadcast seeding methods, dependent upon the extent of seedbed preparation and whether tillage is used or practical to incorporate the seed. For example, if you plant on a freshly prepared seedbed and use a harrow or shallow tillage to incorporate the seed, stand establishment may be about 70% of planted seed. Broadcasting seed on untilled soil, or where previous rainfall has crusted the soil surface will likely reduce wheat establishment to approximately 50% of planted seed. Therefore, appropriate broadcast seeding rates may vary from 120 to over 180 pounds per acre.
Weed control can’t always wait until spring: Most everyone appreciates the importance of weed control during early development for our primary crops, but relatively few employ this concept for wheat. Not only is weed control important with wheat, but it may be more even more difficult because there is a very long time until spring for competition to occur, and weed control options are more limited, compared to what you are likely accustomed to with other crops. Thus, using residual herbicides in the fall can greatly reduce weed competition, reduce issues with spring application timing, and may also help stifle development of weed resistance (which are developing in wheat). Furthermore, employing fall weed control can be less expensive than options during the spring.